This disclosure relates to a data storage medium, and in particular to a data storage medium comprising a high modulus layer used to control the overall degree of flatness in the storage medium.
An increase in data storage density in optical data storage media is desired to improve data storage technologies, such as, but not limited to, read-only media, write-once media, rewritable media, digital versatile media and magneto-optical (MO) media.
As data storage densities are increased in optical data storage media to accommodate newer technologies, such as, but not limited to, digital versatile disks (DVD) and higher density data disks for short and long term data archives such as digital video recorders (DVR), the design requirements for the transparent component of the optical data storage devices have become increasingly stringent. Optical disks with progressively shorter reading and writing wavelengths have been the object of intense efforts in the field of optical data storage devices. Materials and methods for optimizing physical properties of data storage devices are constantly being sought. Design requirements for the material used in optical data storage media include, but are not limited to, disk flatness (e.g., tilt), water strain, low birefringence, high transparency, heat resistance, ductility, high purity, and medium homogeneity (e.g., particulate concentration). Currently employed materials are found to be lacking in one or more of these characteristics, and new materials are required in order to achieve higher data storage densities in optical data storage media. Disk flatness, also referred to as tilt, is a critical property needed for high data storage density applications. Consequently, a long felt yet unsatisfied need exists for data storage media having improved dimensional stability and minimal tilt.